Adding an article
If you're used to using a system like WordPress this is very straightforward. You input an Article just like any normal WordPress Post. You simply go to Articles and select Add New. You will then be presented with the usual WYSIWYG editor and you can categorise and tag as appropriate. For more information on this, please read the article on Standfirst Cloud called Creating a Post.
If you're using feeds to populate your content, this allows you to create additional Kindle only content, which could also include advertisements.